Digi XBee 3 Cellular LTE-M, User Manual, Page: 161 / 331

Socket behavior API mode behavior for incoming UDP data
Digi XBee® 3 Cellular LTE-M/NB-IoT Global Smart Modem User Guide 161
When the IP setting is TCP the XBee Smart Modem allows multiple incoming TCP connections on the
port specified by the C0 setting. Any data received on the connection is sent out the XBee Smart
Modem's serial port as a Receive (RX) Packet: IPv4 - 0xB0 frame.
To send data from the device over the connection, use the Transmit (TX) Request: IPv4 - 0x20 frame
with the corresponding address fields received from the Receive RX frame. In other words:
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Take the source address, source port, and destination port fields from the Receive (RX) frame
and use those respectively as:
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The destination address, destination port, and source port fields for the Transmit (TX) Request
frame.
A connection is closed when:
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The remote end closes the connection.
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No data has been sent or received for longer than the socket timeout set by TS (IP Server
Connection Timeout) .
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A Transmit (TX) Request frame is sent with the CLOSE flag set.
API mode behavior for incoming UDP data
When the IP (IP Protocol) setting is UDP, any data sent from a remote host to the XBee Smart
Modem's network port specified by the C0 (Source Port) setting is sent out the XBee Smart Modem's
serial port as a Receive (RX) Packet: IPv4 - 0xB0 frame.
To send data from the XBee Smart Modem to the remote destination, use the Transmit (TX) Request:
IPv4 - 0x20 frame with the corresponding address fields received from the Receive RX frame. In other
words take the source address, source port, and destination port fields from the Receive (RX) frame
and use those respectively as the destination address, destination port, and source port fields for the
Transmit (TX) Request frame.
Transparent mode behavior for outgoing TCP and TLS
connections
For Transparent mode, the IP (IP Protocol) setting specifies the protocol and the DL (Destination
Address) and DE (Destination port) settings specify the destination address used for outgoing data
(UDP) and outgoing connections (TCP and TLS).
Note For NB-IoT, TCP support is dependent on the network. Contact your network provider for
details.
To initiate an outgoing TCP or TLS connection to a remote host, send data to the XBee Smart
Modem's serial port. If
CI (Protocol/Connection Indication) reports a value of 0 , then the connection
was successfully established, otherwise the value of CI indicates why the connection attempt failed.
Any data received over the connection is sent out the XBee Smart Modem's serial port.
A connection is closed when:
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The remote end closes the connection.
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No data has been sent or received for longer than the socket timeout set by TM (IP Client
Connection Timeout) .
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You make and apply a change to the IP , DL , or DE .